Flea and tick infestation of animals is a health and economic concern for pet owners. Fleas and ticks are known to carry a variety of infectious agents including, but not limited to bacteria, viruses, protozoan parasites, and rickettsia. As such, fleas and ticks are a problem not only when they are on an animal but also when they are in the general environment of the animal.
The medical importance of flea and tick infestation has prompted the development of reagents capable of controlling flea and/or tick infestation. Commonly encountered methods to control infestation are generally focused on use of insecticides, which are often unsuccessful for one or more of the following reasons: (1) failure of owner compliance (frequent administration is required); (2) behavioral or physiological intolerance of the pet to the pesticide product or means of administration; and (3) the emergence of flea and/or tick populations resistant to the prescribed dose of pesticide.
Octopamine receptor is a member of the biogenic amine receptor family, which also includes receptors for dopamine, serotonin, and tyramine. Octopamine is a major neuromodulator in insects with neurotransmitter and neurohormone functions and is a known activator of adenylate cyclase, resulting in stimulation of cyclic AMP production.
Prior investigations have described certain insect biogenic amine receptors in Drosophila melanogaster, including for example, Arakawa et al. 1990, Neuron, 2:343-354, Venter et al., U.S. Pat. No. 5,474,898, Saudou et al., 1990, EMBO Journal, 9(11):3611-3617, and Han et al., 1998, J. Neuroscience, 18(10):3650-3658. Unfortunately, members of the biogenic amine receptor family have proven difficult to clone due to the rarity of the sequence as cDNA and often have highly related sequences and activities, which has resulted in confusion in the art with respect to the true identity of reported sequences.
Insect octopamine receptor is a known target of various insecticides, including formamadine compounds such as demethylchlordimeform (DCDM). However, no formamadine compound to date has been shown to be safe and efficacious for use for treating tick infestations on a host animal. Octopamine receptor is not present in vertebrates and within insects susceptibility to insecticides targeting the octopamine receptor have been shown to vary by species. Therefore, in order to create compounds and treatments which are efficacious against fleas and/or ticks while minimizing toxicity to the host animal or to non-target insects, it would be a distinct advantage to have the sequence of the flea and/or tick octopamine receptor. Accordingly, isolation and sequencing of flea and/or tick octopamine receptor genes may be critical for use in identifying specific agents for treating animals for infestation.